Lapses in mental health care allowed a convicted killer to butcher and eat a man in a London flat.

Today the Old Bailey was told of repeated failings by key professionals after Peter Bryan pleaded guilty to two killings.

Sentencing him to two life sentences, Judge Giles Forrester told him he would never be released because he was too dangerous.

A major row erupted over how he was ever considered to be safe enough to be discharged. Bryan, now 36, was convicted of killing a 20-year-old girl with a hammer in 1993 and sent to Rampton. In 2002 he was freed.

In February 2004, within hours of his release by the East London and City Mental Health Trust, he had killed and dismembered a friend at a Walthamstow flat. He cooked his brain in a frying pan with butter before eating it. The trust today promised a full independent inquiry. Following the Walthamstow killing Bryan was sent to Broadmoor mental hospital where he killed a fellow inmate in a "medium risk room" nine weeks later.

Today at the Old Bailey he pleaded guilty to manslaughter on the grounds of diminished responsibility. He was being sentenced this afternoon. Lawyers are pressing for Bryan to be added to the small number of psychotic killers considered to be too dangerous ever to be released again.

Aftab Jafferjee, prosecuting told the court: "The last two killings took place when Bryan was under the care of the Mental Health Act regime which manifestly failed to protect the public.

"This case reveals a chilling insight into the mind of a man who had literally developed an appetite for killing.

"The circumstances of this offending, his mental condition, the inability of experts to detect when he is at his most dangerous and his settled desire to cannibalise his victims all combine to make him so uniquely dangerous that ... the life sentence to be imposed should be a whole life sentence."

Bryan's killings started in March 1993 when he went round to confront his former boss at a clothes shop in a dispute over money.

Arriving at the shop in the King's Road he battered the boss's daughter Nisha Sheth to death with a claw hammer.

Sent to Rampton maximum security hospital in February 1994, he was granted a conditional discharge in January 2002 and sent to a hostel where residents have their own front door and room key and can "come in and out as they wish." After an allegation-of an indecent assault on a 16-year-old girl, Bryan was sent back to hospital but only as an informal patient on an open ward at Newham General Hospital.

Just hours after being granted as much leave as he wanted Bryan walked out and killed. His victim Brian Cherry, 43, was described by friends as a "friendly, harmless" man. Bryan hacked him to death, severing his arms and legs and inflicting serious head injuries.

Mr Jafferjee said: "That this was a significant failure within the Mental Health Care regime is plain. Even more startling is the fact that such a capacity for failure within this regime was to manifest itself again in just nine weeks time." Bryan was arrested and sent to Broadmoor for assessment pending his appearance at the Old Bailey.

In April last year Bryan attacked inmate Richard Loudwell, 50, himself a killer who was also awaiting sentence. Loudwell from Gillingham, Kent, had pleaded guilty to killing an 82-year-old woman in her home and had been sent to the mental hospital to have his condition assessed.

The East London and the City mental health trust said today an immediate investigation was carried out after the killing. As a result the trust said it has enhanced its specialist community- based forensic teams to strengthen local mental health services.

Sheila Foley, chief executive, said: "I would like to extend my deepest sympathy to the family and friends of Mr Cherry and all those affected by this case.

"The issues raised in this highly unusual case will be the subject of an independent inquiry but I would like to give my personal assurance that the trust is doing and will continue to do everything in its power to improve the services we provide to local people."